1. Technical Field
The present invention relates to an arrayed waveguide grating optical multiplexer/demultiplexer having an arrayed waveguide grating formed on a planar lightwave circuit (PLC).
2. Related Arts
As a prior arrayed waveguide grating optical multiplexer/demultiplexer, the following techniques are known.
(1) A technique to fabricate individually a module (multiplexer) for multiplexing (MUX) having an arrayed waveguide (AWG) and a module (demultiplexer) for demultiplexing (DEMUX) having an arrayed waveguide (AWG).
(2) As disclosed in the following reference (1), a technique to integrate an arrayed waveguide grating for MUX and an arrayed waveguide grating for DEMUX on one chip.
Reference (1): I. Ogawa, et al., “32ch reconfigurable optical add multiplexer using technique for stacked integration of chip-scale-package PDs on silica-based PLC”, ECOC 2006, Tu4.4.2
However, in the case of the above mentioned prior technique (1), at an optical node, it is necessary to install individually a multiplexing (MUX) module and a demultiplexing (DEMUX) module and to store individually the MUX module and the DEMUX module
In the above prior technique (2) disclosed in the reference (1), since the arrayed waveguide grating for MUX and the arrayed waveguide grating for DEMUX are different, each center wavelength of the two arrayed waveguide gratings is slightly different due to the process error in manufacturing. Therefore, in the prior technique (2), it is required to fine adjust each center wavelength of the two arrayed waveguide gratings, by using a phase trimming technology disclosed in the following reference (2). For doing the fine adjustment by using the phase trimming technology, there was a problem that a large-scale device is needed.
Reference (2): J. Abe, et al., “Waveguide tuning in a thermal silica-based arrayed waveguide grating multi/demultiplexer by UV irradiation”, The Institute of Electronics, Information and Communication Engineers, Proceedings of the 2000 General Conference, p 255.